Both our on-going LVRS study and the NETT have been hindered by an underestimation of the difficulty in recruiting patients who qualify for this invasive study. Both studies have evaluated/recruited to date approximately 50% of the projected number of subjects required to achieve statistical power to draw significant clinical conclusions. In fact, the NIH is investing additional funds in the national "marketing" of the NETT and LVRS. We believe that this national marketing effort, as well as changes and enhancement of local recruiting strategies will allow us to enroll adequate patients for study completion. This controlled clinical trial will provide data to address crucial clinical and potential economic implications of this surgical intervention in patients with severe emphysema.